In various industries, turret assemblies are used for moving and manipulating objects. For example, workpieces are mounted on a section or an arm of a turret and moved from one workstation to the next, with each workstation being designed to manipulate the workpiece in a specific way. Other turrets are used to simply transfer an object from one location to another, such as movement from one conveyor to another. The workpieces or objects are attached and detached from such turrets in a wide variety of ways, including the use of vacuum during rotation of the turret.
In the storage battery industry, lead-acid batteries and other types of storage batteries are made with numerous positive and negative electrode plates. During the assembly of such batteries, the electrode plates and handled by a variety of machines. In a typical manufacturing process, the electrode plates are initially placed in stacks designated either as positive or negative. The negative and positive stacks are separated into individual plates which are later reassembled in an alternating or staggered formation within the battery casing. Initially, the plates of the negative stacks are handled on separate equipment from the plates of the positive stacks.
The equipment may include a conveyor that moves each stack to a location where the individual plates are broken loose from one another. This step is necessary since some electrode plates, such as lead battery plates, tend to adhere to one another. After the electrode plates are broken loose, they are moved to a second conveyor which directs them to another workstation for eventual combination with the electrode plates of opposite polarity.
Problems can arise in moving individual electrode plates from the stack of plates to the second conveyor. Such problems include selecting and manipulating individual plates from the stack of plates, and depositing them safely at a second location. Lead electrode plates are particularly troublesome since they tend to be relatively heavy, porous, and fragile. Consequently, special provisions must be made for separating and moving an individual plate from a stack and presenting it to a conveyor at a second location.
A reel-type assembly having two reel ends connected by rods has been used to transfer such plates. Rotatable suction cup assemblies are mounted on the rods and their respective rotations are appropriately timed to bring the suction cups into contact with the outermost plate in a stack of plates. The suction cups contact the plate, pick it up, rotate it over the top of the reel, and position it at a second location, e.g. on a conveyor. With this complex arrangement, it is difficult to achieve the desired dependability and operating speeds required in modern battery assembly plants.
Traditional turret systems have also proved to be problematic for moving objects such as battery electrode plates. The individual plates are difficult to pick up and move to a second location without risk of breakage or poor orientation at the second location. Even with existing vacuum turrets, sufficiently fast, consistent movement of such objects cannot be achieved. If the vacuum is too low, the heavy lead plates are not picked up quickly enough, if at all. However, if the vacuum is increased, there is added risk of breakage or of lifting more than one plate at a time. The porosity of such electrode plates allows the vacuum to sometimes pick up a second plate.
Existing systems also present other problems since they do not adequately hold the plates in a stable fashion during the rapid movement from a first location to a second location. The heavy planar electrode plate can sway or twist, leading to additional breakage or misalignment of the plate when it is deposited at the second location.
The present invention addresses the problems described above and provides an apparatus for consistent, rapid movement of individual objects from a first location to a second location.